Overall I liked your rides - they were nice and in control with a lot of good basics, which is where you should be at this point.
For your rein length, I actually like where they are at. You have more control here than you would have if you lengthened them, and you do not have too tight a hold. A couple of times I actually saw a little loop of rein in between the jumps, a sure sign that the reins are not too tight. You might need a slightly bigger release up your pony's neck, though, to allow him to use his body more.
For your lower body, you might need to shorten your stirrups a hole. You also look like you are pinching some at your knee. Think about keeping your calf on the horse and using that area to drive him up into the bit (helping to bring his head down). Also step down into your stirrups before the jumps. Your heels sometimes float a bit over the fences.
For your pony, work on keeping him bent in the direction of travel. He is often looking to the outside on the corners, allowing him to drop his shoulder and this will make it hard to get the lead changes and will affect your rhythm to the jump. Overall he keeps a nice even pace, which is oh so important at this point and he took you to nice spots pretty consistently.
Good job overall, you are going in the right direction.